This invention is directed to a security system for storage compartments, and more particularly, to a latch assembly and master lock assembly mounted in the compartment interior for securing access doors of the compartment wherein the interior latch and master lock assembly may be operated by a tamper-resistant control on the compartment exterior while the latch and lock assemblies have no exterior components capable of destruction from outside the compartment.
Every year, millions of dollars in equipment are stolen from construction sites. Often, a single piece of equipment costs thousands of dollars. In addition to the loss of equipment, the time taken to replace even the most inexpensive equipment can be great. Construction delays can result in thousands, if not millions of dollars in construction contract damages, lost revenue, and other costs.
At the construction site, storage containers are usually provided to store this equipment and used to deter theft thereby saving significant money and time. However, many of these containers have no, or only simple locking devices that have little effect against theft. Additionally, these devices can be defeated externally with little effort, are overly burdensome, unnecessarily complicated and do little to actually make the containers more secure.
For example, an external padlock can be easily defeated with bolt cutters. To compound the problem, a typical situation of individual insider theft occurs by one employed at a construction site who, for example, may be specifically skilled in metalworking. Such an individual has little trouble cutting through external locking systems.
Previous attempts to address the problem of theft from storage compartments using an internally mounted security system have only produced weak solutions that are easily defeated and provide a false sense of security. For example, U.S. Pat. Nos. 3,933,382 and 5,760,703 disclose security locks for the door of a cargo truck. The locks operate using a single electrically controlled bolt which locks with a wheel track of the door assembly, or in a bracket carried by the door. There is no other lock or latch assembly utilized to prevent the door from being unlocked. Overcoming a single lock is relatively straight forward and may easily be done to open the door.
U.S. Pat. No. 4,866,963 discloses a security system for locking doors on a cargo truck. The system employs a latch assembly carried on the exterior of the doors, but the latch assembly has no lock. Again, only a single bolt, as discussed above, on the interior side of the door is utilized to lock and secure the door. Because there is no cooperation between the exterior latch assembly and the internally mounted security bolt, only a single bolt secures one of the two large storage compartment doors, which can be easily defeated.
U.S. Pat. No. 6,298,699 shows a typical electronic combination lock for a residential or commercial entrance door having a dial-shaped handle with a keypad incorporated therein. When the correct combination is selected a deadbolt may be unlocked. This type of locking mechanism is not meant for use in a security system needed to control access to a large cargo container.
Accordingly, an object of the present invention is to provide a security system mounted on the interior of a storage compartment which does not have externally mounted components that may be tampered with to attempt to gain access to the compartment interior.
Another object of the present invention is to provide a security system for a storage container which is cost efficient, easy to use, and requires multiple components to be defeated in order to open the lock and gain access to the interior of the storage compartment.
Another object of the present invention is to provide a security system for a storage compartment wherein the main latch assembly for securing the door includes multiple internal securing points operated from a single internally mounted main latch assembly that is controlled by a tamper-resistant control for locking and unlocking the storage compartment doors.
The above objectives are accomplished according to the present invention by providing a security system for preventing unauthorized access to a storage compartment wherein the compartment has an entryway for allowing access to a compartment interior, and a door closing said entryway and preventing access to the compartment interior. The security system includes a latch assembly carried by the door for latching the door in a closed position with the storage compartment. In accordance with the invention, the latch assembly is disposed entirely on an interior side of the door within the compartment interior. The latch assembly has an engaged position to latch the door in the closed position in which the entryway is closed, and a disengaged position wherein the door may be opened to provide access to the compartment interior. At least one reciprocating latch element is included in the latch assembly for latching the door with the storage compartment when the latch assembly is in the engaged position. A receiving member is carried by the storage compartment for receiving the latch element so that the latch element and receiving member latch the door in the closed position. A latch actuator is included in the latch assembly for moving the latch assembly between the engaged and disengaged positions. An operator connects with the latch actuator that is manually operable from outside the compartment for operating the latch actuator on the interior side through the door.
Advantageously, a master lock assembly is operatively connected to the latch assembly on the interior side for controlling whether the latch actuator may be operated. The master lock assembly includes a first locking part interlocking with a second locking part carried by the latch assembly. The master lock assembly has a locked position wherein the first locking part is locked together with the second locking part to prevent the latch assembly from being moved to the disengaged position, and an unlocked position wherein the first and second locking parts are unlocked so that the latch assembly may be moved to the disengaged position. The master lock assembly is carried within the compartment interior to prevent destruction of the master lock assembly from outside the compartment. A master lock actuator is provided for manually operating the master lock assembly from outside the storage compartment.
A tamper-resistant master lock control is provided for controlling the master lock assembly between the locked and unlocked positions from outside the compartment, whereby access to the compartment interior is prevented when the latch assembly is in the engaged position and the master lock assembly is in the locked position.
In another embodiment, a main latch assembly is entirely on an interior side of a first door within the compartment interior, and a secondary latch assembly is carried by a second door for latching the second door in a closed position with the storage compartment. The secondary latch assembly is disposed entirely on an interior side of second door within the compartment interior. A plurality of main latch elements is included in the main latch assembly for latching the first door with top and bottom portions of the storage compartment. A horizontal reciprocating latch element is included in the main latch assembly for actuating the secondary latch assembly and latching the second door in the closed position together with the first door and the storage compartment. The secondary latch assembly includes a plurality of secondary reciprocating latch elements for latching the second door with top and bottom portions of the storage compartment. A main latch actuator is included in the main latch assembly connected to the plurality of main latch elements for moving the main latch elements to latch the first door with the storage compartment and actuating the secondary latch assembly. A secondary latch actuator is included in the secondary latch assembly that is operated by the horizontal reciprocating latch element. The secondary latch actuator being connected to the plurality of secondary reciprocating latch elements for moving the secondary latch elements to latch the second door with the storage compartment. An operator is provided that is manually operable from outside the compartment for operating the latch actuator on the interior side through the door, whereby access to the compartment interior is prevented when the main latch assembly is operated to latch together with the second door and the storage compartment.
In a particularly advantageous embodiment, the main latch actuator is a rack and pinion mechanism carried by the first door having a pinion meshing with a plurality of toothed racks. The operator engages and rotates the pinion which converts the rotary movement of the pinion to the linear movement of the racks in order to operate the main latch assembly. The racks being connected to the main latch elements so that when the pinion is rotated by the operator the main latch elements latch the first door to the storage compartment and actuate the secondary latch assembly. The secondary latch actuator includes an abutment bar which is engaged and operated by the horizontal reciprocating latch element. The abutment bar is pivotally connected to an upper pivot arm and a lower pivot arm. The upper and lower pivot arms are each pivotally connected to one of the secondary reciprocating latch elements so that when the abutment bar is operated, the pivot arms extend the secondary reciprocating latch elements to latch the second door. A guide member is carried by the abutment bar which is received by a guide bracket carried on the interior side of the second door to maintain the abutment bar in fixed vertical alignment with the horizontal latch element.
In an alternative embodiment, the latch actuator includes a rotary hub connected to two vertical reciprocating rods which engage with the top and bottom sides of the storage compartment when the hub is rotated to the engaged and locked position by the operator. The first locking part comprises a deadbolt that is received in a slot formed in the rotary hub which comprises the second locking part in order to prevent the hub from rotating when in the locked position. The deadbolt is raised out of the slot by the master lock actuator which includes an external storage compartment handle on the outside of the compartment connected to a lifting bar which moves the deadbolt to the unlocked position. When the handle is rotated, the bar lifts the deadbolt and allows the hub to be rotated by a second handle on the outside of the storage compartment door.
To prevent the deadbolt from being moved and the latch assembly disengaged by anyone who wanders by, a deadbolt stop is provided which is displaced vertically over the deadbolt. The deadbolt stop prevents the deadbolt from being raised until the deadbolt stop is rotated horizontally. In one embodiment, a solenoid is attached to the stop by a solenoid arm and connector linkage. When power is supplied to the solenoid, the solenoid arm is retracted and the deadbolt stop moved to allow the deadbolt to be lifted to the unlocked position. Power is supplied to the solenoid through a remote control device or key switch that completes an electrical circuit and gives power to the solenoid.
When the power is removed from the solenoid, the deadbolt returns to the locked position. In an alternative embodiment, the solenoid is replaced with an external combination locking mechanism. The locking mechanism is directly connected to the deadbolt stop, and, when the proper combination is entered, the locking mechanism may be rotated and the deadbolt stop moved to allow the deadbolt to be raised and the hub rotated.